1. Field of the Invention
The embodiments of the invention generally relate to tools, and more particularly to a tool used to drive a bone screw implant assembly used in the field of surgical lumbar, thoracic and cervical spine treatment.
2. Description of the Related Art
Surgical procedures treating spinal injuries are one of the most complex and challenging surgeries for both the patient and the surgeon. When there are various deformities, trauma, or fractures of the vertebra, surgeons may attempt to “fuse” them together by attaching screw-like assemblies into the pedicles of the spine and thereby connecting several vertebrae (typically two or more) using a semi-rigid rod. These screw-like assemblies may include the type of assemblies described in U.S. patent application Ser. No. 11/045,908, filed Jan. 28, 2005 and entitled, “Polyaxial Pedicle Screw Assembly,” the complete disclosure of which in its entirety is herein incorporated by reference. Generally, assemblies such as these include a bone screw and a screw head attached to the bone screw.
Those in the industry, as well as orthopedic surgeons, have acknowledged that having a bone screw pre-attached to the screw head prior to the time of the surgical operation, and preferably being attached by the manufacturer, is advantageous as it reduces the overall time associated with performing the operation. However, once a pre-attached pedicle screw assembly (combined bone screw and screw head) is received by the surgeon, he/she still has to screw (drive) the bone screw into the bone. Unfortunately, most conventional tools cannot drive the bone screw into the bone with the screw head attached due to the spatial limitations inside of the patient and the overall complex geometry resulting from the pedicle screw assembly (combined bone screw and screw head). Thus, there remains a need for a new tool to drive these pedicle screw assemblies (combined bone screw and screw head) into the bone, thereby reducing the overall surgical time and providing the surgeon with improved intra-operative flexibility.